OR
You can upgrade the plugin using WordPress automatic upgrade in WordPress Admin >> Plugins page.

IMPORTANT: **Upgrade with caution.
To safely upgrade WassUp when your site is busy, you should temporarily stop WassUp recording of new visitors manually (uncheck Enable/disable recording in WassUp >> Wassup-Options >> [Statistics Recording] Tab), then do the automatic upgrade, and afterwards, re-enable WassUp recording manually.

Usage:

When you activate this plugin (as described in "Installation"), it works "as is". You don't have anything to do. Wait for visitors to hit your site and start seeing details (click the dashboard and go to WassUp page)

IMPORTANT: WassUp is incompatible with page-based caching plugins such as "WP Super-Cache".